The Manchaca one is a bit tricky though, and a lot of people get confused because it is true the town is Manchaca "Man-chock-a". But there's a school there named after a person Menchaca "Men-chock-a". The town was actually named Manchaca after the Manchaca Springs in the area. However, the springs were named after José Antonio Menchaca.
I've heard people say "Man-chack" (Road) and even "Man-shack". It's about as appropriate as calling Lavaca Street or the river by the name "La-vack". I live almost within sight of Manchaca Road, so I hear it all.
I am guilty of calling Guadalupe "Gwod-a-loop" sometimes. But I only call the street that. The river is of course "Gwod-a-lupay" as it should be.